The General Clinical Research Center of the University of Rochester provides the basic needs for most of the clinical investigation done in the institution. Thirty one investigators used the center during the past year. Projects undergoing study include 1) nutrition in cancer, 2) mechanism of the hormonal responses to insulin induced hypoglycemia, 3) use of penicillamine in primary biliary cirrhosis and its effect on copper and zinc metabolism, 4) the effects of glucose and amino acid ingestion on forearm muscle metabolism in myotonic dystrophy, 5) acetazolamide treatment in periodic paralysis, 6) the use of insulin hypoglycemia as a test for prolactin reserve, 7) the effect of tryptophane ingestion of the release of pituitary hormones, 8) the relationship of serum fluoride to changes in bone metabolism, 9) the efficacy of metronidozole in certain patients with intestinal bypass, 10) the relationship of uric acid and calcium excretion in idiopathic hypercalcuria, and 11) factors influencing the metabolism of injected gammaG globulin in patients with hypogammaglobulinemia.